Spark-plug.



PATENTED MAY 26, 1908.

BIBRUDBN. SPARK PLUG. APPLIOATION FILED vFEB. 10, 1908.

WI TN ESSES INVENTOR,

l JAA ATTORNEY `o the explosion chamber.

UNITED STATES PATENT onirica."

ELIGHA BRUDEN, OF SAN FRANCISCO, CALIFORNIA.

SPARK-PLUG.

Application mea-February 10,1908. serrano. 415,018.

explosive' engines, the object ofthe inven-V tlon being to provide .an improved form of a 'spark plug, the use of whic 1 will not be accompanied by the deposition ofcarbon .upon the plug, and which will therefore remain clean for an indefinite period.

In the accompanying drawing, Figure l is a side view of my im provedspark plug; Fig. 2. is a longitudinal sectional View of the same,

the holder being shown in side elevation; Fig.

3 is a side View of the porcelain Wire holder; Fig. 4 is a sectional View thereof.

Referring to theA drawing, '1 indicates a porcelain holder, through which pass wires 2 and 3 connected with platinum terminals,4, 5. The long wire 2 extends through the whole length of the plug, an'd Ais provided with thev usual binding screw 6, but the short wire 3 passes through only the thick inner portion of the holder, and its end?, 'terminates in the sloping rear surface or shoulder 8 of Said thick portion. Upon the outer end of said holder is placed the inner sleeve 9, which has a corneal innersurfaee adapted' to Contact with the end 7 of the short wire 3,;its. out-er surface being threadednd screwed into the internally threaded sleeve 10, which -`is' formed tapering or conical on the inside to'` conform to the inner slo ing surface of the holder, a sheet 11 of as estos being interv posed between said sloping surfaces. By

screwing said sleeve 10 upon the sleeve 9 the latter is drawn tightly against the exposed end of the Wire 3. 'lhe sleeve l. 0 is externally threaded, in the usual manner, as'shown at l2, for the purpose of screwing it into the wall The advantage of this construction is that both of the plativnum points are separated from metallic parts by a sulicient body of porcelain to prevent any deposition of carbonl on either of said polnts. When onev of said terminal points is connectedwith metal 'close to said point, as has been the custom, there is a tendency for carbon to deposit on said material,

- specification of Letters Patent.`

my hand in the witnesses.

Patented May se, ieee.

plugv becomes very ine'licient. ith-'my iinproved spark plug, this objection is avoided. I claimzn 1. A s ark plug having a wire holder of non-con ucting material and having a rear shoulder, two wires therethrough, having 'so that, in time, ldue to this eoatin the spark i .60 exposed points adjacent to each other, be-V tween which the spark can pass, one of said wires extending to the outer vend oli the holder, and the other Wire extending to said `shoulder and being there exposed, and a metallic sleeve for the holder in contact with saidj exposed end and provided with means for securing it in the wall of an explosion y chamber. I

2. A spark plug comprisinga wire holder' of non-conducting material, two wires ex tending therethrough, and terminating in adjacent points, one of said wires 'extending substantially the full length of said holder,

Ameans for connecting said wire with an electiic'circuit, the other wireexte'nding only to' an'intermediate portion of said holder, a me-- tallicsleevearound said holder arranged iii contact with the end of said latter wire', and a sleeve screwedto the first sleeve, and pro-4 videdwith means for securing it in the wal?-` of an explosion chamber, substantially' as described. f -A j 3. A spark plug comprisinga wire holderl of non-conducting material, two' wires extending therethrough, and terminating in.

ad'acent points,l one of said wires extending su stantially` the lull length of said holder, means for connecting s'aid'wirewith an elec tric circuit, the other wire extending only to an intermediate portion of saidholc'ler, a me` tallic'sleeve around said holder arranged in contact withlthe end of said latter wire, a

sleeve'screwed to the rst sleeve, and provided'with means for securin it in the wall of an explosion chamber, an a sheet of asbestos 'inter osed betweenthe second'sleeve' and the hol er, substantially as described.

In testimony whereof I have hereunto set presence of two subscribing ,.ELTGHA BRUDEN. Witnesses Y FRANCIS M. WRIGHT,

RICHARDS. 

